Aligner evaluation system, aligner evaluation method, a computer program product, and a method for manufacturing a semiconductor device

ABSTRACT

An aligner evaluation system includes (a) an error calculation module configured to calculate error information on mutual optical system errors among a plurality of aligners; (b) a simulation module configured to simulate device patterns to be delineated by each of the aligners based on the error information; and (c) a evaluation module configured to evaluate whether each of the aligners has appropriate performances for implementing an organization of a product development machine group based on the simulated device pattern.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. P2002-234053, filed on Aug.9, 2002; the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to technology for manufacturing asemiconductor device, and, more particular, relates to an alignerevaluation system, an aligner evaluation method, an aligner evaluationprogram, and a method for manufacturing a semiconductor device usedtherein.

2. Description of the Related Art

A photolithography process is generally performed as a manufacturingprocess of semiconductor devices. Optical system errors attributable toaberration of a projection lens of an aligner used in thephotolithography process and errors attributable to a difference in anillumination optical system represent unique values to each aligner.Accordingly, those errors vary delicately with aligners even of the sametype. Therefore, if optimized exposure conditions for a new product in aparticular aligner are applied to another aligner, it is possible thatthe latter aligner is not applicable to development of the new product(product development) because of inter-aligner variation in devicepattern shapes formed on an exposure object, which is attributable tothe optical system errors of each aligner. Accordingly, it is necessaryto determine whether each aligner for performing the product developmenthas an appropriate performance to facilitate the organization of aproduct development machine group.

Conventional device pattern simulation has been conducted withoutconsidering such optical system errors among the aligners. Accordingly,it has not been possible to determine from a group of aligners as towhether those aligners severally have appropriate performances forimplementing an organization of a product development machine group fora new product. For this reason, conventionally, it has been necessary tocarry out optimization of the exposure conditions for each of thealigners having delicately variable optical performances with respect toone another. Moreover, each of the aligners has been evaluated whetherthe aligner has the appropriate performances for implementing anorganization of the product development machine group by a sequence ofprocesses encompassing: exposure using a mask (reticle) for delineatingdevice patterns of a product; development of the patterns; andmeasurement of shapes of the delineated patterns. As a consequence,product development has involved considerable time and effort.

SUMMARY OF THE INVENTION

A feature of the present invention inheres in a evaluation systemincluding (a) an error calculation module configured to calculate errorinformation on mutual optical system errors among plurality of aligners;(b) a simulation module configured to simulate device patterns to bedelineated by each of the aligners based on the error information; and(c) an evaluation module configured to evaluate whether each of thealigners has appropriate performances for implementing an organizationof a product development machine group based on the simulated devicepattern.

Another feature of the present invention inheres in a evaluation methodincluding (a) calculating error information on mutual optical systemerrors from among a plurality of aligners; (b) simulating devicepatterns to be delineated by each of the aligners based on the errorinformation; and (c) evaluating whether each of the aligners hasappropriate performances for implementing an organization of a productdevelopment machine group based on the simulated device pattern.

An additional feature of the present invention inheres in a computerprogram product for executing an application on an aligner evaluationsystem, the computer program product providing (a) instructionsconfigured to calculate error information on mutual optical systemerrors of a plurality of aligners; (b) instructions configured tosimulate device patterns to be delineated by each of the aligners basedon the error information; and (c) instructions configured to evaluatewhether each of the aligners has appropriate performances forimplementing an organization of a product development machine groupbased on the simulated device pattern.

A further feature of the present invention inheres in a method formanufacturing a semiconductor device including (a) determining a layoutof a device pattern; (b) producing a set of masks based on thedetermined layout; (c) calculating error information on mutual opticalsystem errors of the plurality of aligners, simulating device patternsto be delineated by each of the aligners based on the error information,evaluating whether each of the aligners has appropriate performances forimplementing an organization of a product development machine groupbased on the simulated device pattern; (d) coating a photoresist film ona semiconductor wafer; and (e) exposing the photoresist film with one ofthe masks employing the aligner evaluated to have the appropriateperformances.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing the configuration of an alignerevaluation system according to an embodiment of the present invention.

FIG. 2 is another block diagram showing the configuration of the alignerevaluation system according to the embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of an evaluationserver according to the embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a first factoryaccording to the embodiment of the present invention.

FIG. 5 is a flowchart for explaining an aligner evaluation methodaccording to the embodiment of the present invention,

FIG. 6 is another flowchart for explaining the aligner evaluation methodaccording to the embodiment of the present invention,

FIG. 7 is an additional flowchart for explaining the aligner evaluationmethod according to the embodiment of the present invention,

FIG. 8 is a plane view showing a first pattern according to a firstprojection lens adjustment processing modification.

FIG. 9 is a graph showing sensitivity of the first pattern correspondingto Zernike coefficients according to the first projection lensadjustment processing modification.

FIG. 10 is a graph showing wavefront aberration of the projection lenscorresponding to Zernike coefficients before adjustment according to thefirst projection lens adjustment processing modification.

FIG. 11 is a graph showing wavefront aberration of the projection lenscorresponding to the Zernike coefficients after adjustment according tothe first projection lens adjustment processing modification.

FIG. 12 is a graph showing the lateral differences (diamonds) of thefirst pattern of the projection lens delineated by the aligner beforeadjustment, and the lateral differences (squares) of the first patternof the projection lens delineated by the aligner after adjustment,according to the first projection lens adjustment processingmodification.

FIG. 13A is a plane view showing the configuration of a second patternaccording to the second projection lens adjustment processingmodification.

FIG. 13B is a plane view showing the configuration of another secondpattern according to the second projection lens adjustment processingmodification.

FIG. 14 is a graph showing Z9 and Z12 image heights (image widths) ofthe second pattern delineated by the aligner before adjusting theprojection lens according to the second projection lens adjustmentprocessing modification.

FIG. 15 is a graph showing Z9 and Z12 image heights (image widths) ofthe second pattern delineated by the aligner after adjusting theprojection lens according to the second projection lens adjustmentprocessing modification.

FIG. 16 is a graph showing the critical dimension (CD) of image width ofa direction pattern of length and the image height of a transversedirection pattern delineated by the aligner before adjusting theprojection lens according to the second projection lens adjustmentprocessing modification.

FIG. 17 is a graph showing the critical dimension (CD) of image width ofa direction pattern of length and the image height of a transversedirection pattern delineated by the aligner after adjusting theprojection lens according to the second projection lens adjustmentprocessing modification.

FIG. 18 is a graph showing the critical dimension (CD) of image width ofthe direction pattern of length, and the image height of a transversedirection pattern delineated by the aligner after further adjustinguneven illuminance after adjusting the projection lens according to thesecond projection lens adjustment processing modification.

FIG. 19 is a flowchart for explaining a process for manufacturing asemiconductor device according to the embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments of the present invention will be described withreference to the accompanying drawings. It is to be noted that the sameor similar reference numerals are applied to the same or similar partsand elements throughout the drawings, and the description of the same orsimilar parts and elements will be omitted or simplified.

In the following descriptions, numerous specific details are set fourthsuch as specific signal values, etc. to provide a thorough understandingof the present invention. However, it will be obvious to those skilledin the art that the present invention may be practiced without suchspecific details.

(Aligner Evaluation System)

As shown in FIG. 1, an aligner evaluation system according to anembodiment of the present invention includes a headquarters 1, and aplurality of (first to n-th) factories 5 a, 5 b, 5 c, . . . , and 5 nwhich are connected to the headquarters 1 through a communicationnetwork 3. The Internet, an intranet and the like are applicable to thecommunication network 3. As shown in FIG. 2, an evaluation server 2connected to the communication network 3 is located in the headquarters1. Moreover, the first factory 5 a includes a plurality of aligners 6 a,6 b, 6 c, . . . , and 6 n and a measuring device 7 a, each of which isconnected to the communication network 3. Similar to the first factory 5a, each of the second to n-th factories 5 b, 5 c, . . . , and 5 nincludes a plurality of aligners and a measuring device. The evaluationserver 2 is for managing the plurality of aligners and the measuringdevice located in each of the plurality of factories 5 a to 5 n byexchanging information written in the extensible markup language (XML)through the communication network 3.

In the following, for the purpose of simplification, description will bemade regarding the case where the evaluation server 2 exchangesinformation with the plurality of aligners 6 a to 6 n and the measuringdevice 7 a which are located in the first factory 5 a.

As shown in FIG. 3, the evaluation server 2 includes a centralprocessing unit (CPU) 10, and a program storage unit 12, a machinemanagement database 13, a mask design information database 14, an inputdevice 15, an output device 16, a temporary storage device 17, acommunication interface (communication I/F) 18 which are connected tothe CPU 10.

The CPU 10 includes an error calculation module 10 a, a simulationmodule 10 b, a evaluation module 10 c, an exposure condition extractionmodule 10 d, a virtual dangerous pattern extraction module 10 e, acoordinate value extraction module 10 f, a coordinate system conversionmodule 10 g, a coordinate value transmission module 10 h, an actualdangerous pattern reception module 10 i, a confirmation module 10 j, anadjustment value calculation module 10 k, an adjustment valuetransmission module 10 l, a correction module 10 m, a virtualizationmodule 10 n, and an alternative pattern extraction module 10 o.

The error calculation module 10 a calculates error information on mutualoptical system errors from among the plurality of aligners 6 a to 6 nshown in FIG. 2. Here, the error information on the optical systemerrors pertains to information on errors attributable to differences inaberrations of the respective projection lenses, information on errorsattributable to differences in illumination optical systems of theplurality of aligners 6 a to 6 n. The aberration of the projection lensincludes wavefront aberrations such as spherical aberration, comaaberration, and astigmatism. The wavefront aberration can be expressedby use of the Zernike polynomials. The Zernike polynomials includeZernike coefficients of first to thirty-sixth terms. In ascending orderstarting from the first term, the respective Zernike coefficientsrepresent aberration of higher degrees in a radial direction. The errorsattributable to the differences in the aberration of the projectionlenses are obtained by being converted into the Zernike coefficients.The errors attributable to the differences in the illumination opticalsystems include uneven illuminance, axial misalignment, variation ofcoherence factors σ of the illumination optical systems, and the like,which are calculated in quantitative values. The coherence factor σ ofthe illumination optical system is an index representing brightness ofthe illumination optical system. The coherence factor σ can be expressedas σ=NA₁/NA₂ where NA₁ is a lens numerical aperture of the illuminationoptical system (a condenser lens) viewed from a mask side and NA₂ is alens numerical aperture of a reducing projection lens viewed from themask side. Light, which is obliquely incident on the mask, is increasedas the coherence factor σ becomes larger, whereby light contrast on awafer varies. The calculated information on the optical system errors isstored in an error information storage unit 13 a of the machinemanagement database 13.

The simulation module 10 b simulates device patterns to be delineated ona wafer surface by exposure with masks for each of the aligners 6 a to 6n, based on the error information on the optical system errors, machinequality control information (machine QC information), and lithographyconditions which are respectively stored in the error informationstorage unit 13 a, a machine quality control information storage unit 13l, and a lithography condition storage unit 13 b of the machinemanagement database 13, as well as on computer-aided design (CAD) datastored in a CAD data storage unit 14 a of the mask design informationdatabase 14. The machine quality control information includesparameters, for each of the aligners 6 a to 6 n, such as the numericalaperture NA of the projection lens, the coherence factor σ of theillumination optical system, a ring-band ratio, and a focal depth (focusvalue). The lithography conditions include parameters, for each of thealigners 6 a to 6 n, such as an exposure amount (dose amount) and a maskbias (amount of displacement of the mask pattern from a designed value)determined based on the machine quality control information. Asimulation result is stored in a device pattern storage unit 13 d of themachine management database 13.

The evaluation module 10 c evaluates whether each of the aligners 6 a to6 n has appropriate performances for implementing an organization of theproduct development machine group, based on the simulation result storedin the device pattern storage unit 13 d. To be more precise, theevaluation module 10 c evaluates whether each of the device patternssimulated by the simulation module 10 b satisfies design specifications.Moreover, the evaluation module 10 c evaluates that the aligners, thedevice patterns of which have been evaluated to satisfy the designspecifications, for example, the aligners 6 a to 6 f have theappropriate performance for implementing an organization of the productdevelopment machine group. Here, the design specifications areregulations including minimum pattern dimensions and minimum spacedimensions of respective layers of a device, a relation of interlayerpattern positions, and the like. It is possible to product a desireddevice when standard values of the design specifications are satisfied.Here, the standard values of the design specifications are determinedappropriately depending on design guidelines of a new product.

The exposure condition extraction module 10 d extracts exposureconditions such as exposure light intensity and exposure time which aremost suitable for device patterns corresponding to the respectivealigners 6 a to 6 n, based on the simulation result stored in the devicepattern storage unit 13 d, the machine quality control informationstored in the machine quality control information storage unit 13 l, andthe like. The extracted exposure conditions are stored in an optimumexposure condition storage unit 13 e of the machine management database13.

The virtual dangerous pattern extraction module 10 e extracts a pattern,as a “virtual dangerous pattern,” which cannot or can barely achieve thedesirable shapes due to small lithography latitude out of the simulateddevice patterns, based on the simulation result stored in the devicepattern storage unit 13 d. The extracted virtual dangerous pattern isstored in a virtual dangerous pattern storage unit 13 f of the machinemanagement database 13. Here, standard values for extraction of thevirtual dangerous pattern are appropriately determined depending ondesign guidelines of each new product.

The coordinate value extraction module 10 f extracts coordinate valuesof a mask pattern on a mask corresponding to the virtual dangerouspattern (such coordinate values will be hereinafter referred to as“dangerous pattern coordinate values”) out of the CAD data stored in theCAD data storage unit 14 a of the mask design information database 14.The extracted dangerous pattern coordinate values are stored in acoordinate value storage unit 13 g of the machine management database13. Moreover, the coordinate system conversion module 10 g converts thedangerous pattern coordinate values stored in the coordinate valuestorage unit 13 g into coordinate values suitable for the measuringdevice 7 a shown in FIG. 2 (such coordinate values will be hereinafterreferred to as “measurement coordinate values”). The measuring device 7a is for measuring pattern shapes of photoresist to be delineated on awafer. When a scanning electron microscope (SEM) is used as themeasuring device 7 a, for example, a coordinate system of the dangerouspattern coordinate values is converted into a coordinate system of ascanning surface for scanning a wafer surface, and the measurementcoordinate values are thereby obtained. The measurement coordinatevalues are stored in a measurement coordinate value storage unit 13 h ofthe machine management database 13 shown in FIG. 3. The coordinate valuetransmission module 10 h transmits the measurement coordinate valuesstored in the measurement coordinate value storage unit 13 h to themeasuring device 7 a, shown in FIG. 2, connected with the communicationI/F 18 through the communication network 3.

The actual dangerous pattern reception module 10 i receives, through thecommunication network 3, a measurement result by the measuring device 7a concerning a shape of a photoresist pattern which is actuallydelineated by projection of the virtual dangerous pattern onto anexposure object (photoresist) by each of the aligners 6 a to 6 n (such apattern will hereinafter be referred to as “actual dangerous pattern”).The confirmation module 10 j compares the shape of the actual dangerouspattern of the photoresist received by the actual dangerous patternreception module 10 i with the shape of the virtual dangerous patternstored in the virtual dangerous pattern storage unit 13 f, and therebyconfirms whether the shape of the actual dangerous pattern coincideswith the shape of the virtual dangerous pattern.

The adjustment value calculation module 10 k calculates an adjustmentvalue for the projection lens of each of the aligners 6 a to 6 n, whichis necessary for improvement in the device pattern to be projected onthe photoresist film, based on the error information on the opticalsystem errors stored in the error information storage unit 13 a. Theadjustment value transmission module 10 l transmits, through thecommunication network 3, the adjustment values for the respectiveprojection lenses calculated by the adjustment value calculation module10 k to error correction mechanisms 63 a, 63 b, 63 c, . . . , and 63 nwhich adjust the projection lenses of the corresponding aligners 6 a, 6b, 6 c, . . . , and 6 n shown in FIG. 2.

The correction module 10 m performs an optical proximity correction byupdating parameters such as exposure amounts and mask biases for therespective mask patterns of the plurality of aligners 6 a to 6 n basedon optical proximity correction (OPC) amounts stored in an OPC amountstorage unit 13 j of the machine management database 13. Opticalproximity correction is a method for correcting an optical proximityeffect (OPE), which represents deviation of the exposure conditions inthe periphery of mutually adjacent patterns from the optimum values.

The virtualization module 10 n simulates a plurality of virtual devicepatterns having different shapes from the device patterns simulated bythe simulation module 10 b. The alternative pattern extraction module 10o extracts an alternative pattern out of the plurality of virtual devicepatterns simulated by the virtualization module 10 n instead of thevirtual dangerous pattern. The alternative pattern has a different shapefrom the shape of the virtual dangerous pattern but has an identicalfunction.

Furthermore, CPU 10 further includes a control module not shown. Thecontrol module controls input and output of the signals, and operationof the error calculation module 10 a, the simulation module 10 b, theevaluation module 10 c, an exposure condition extraction module 10 d,the virtual dangerous pattern extraction module 10 e, the coordinatevalue extraction module 10 f, the coordinate system conversion module 10g, the coordinate value transmission module 10 h, the actual dangerouspattern reception module 10 i, the confirmation module 10 j, theadjustment value calculation module 10 k, the adjustment valuetransmission module 10 l, the correction module 10 m, the virtualizationmodule 10 n, the alternative pattern extraction module 10 o, the programstorage unit 12, the machine management database 13, the mask designinformation database 14, the input device 15, the output device 16, thetemporary storage device 17, the communication I/F 18 shown in FIG. 3,and, the aligners 6 a-6 n and the measuring device 7 a.

In consideration of the load of the CPU 10, the functions provided bythe CPU 10, i.e., the error calculation module 10 a, the simulationmodule 10 b, the evaluation module 10 c, the exposure conditionextraction module 10 d, the virtual dangerous pattern extraction module10 e, the coordinate value extraction module 10 f, the coordinate systemconversion module 10 g, the coordinate value transmission module 10 h,the actual dangerous pattern reception module 10 i, the confirmationmodule 10 j, the adjustment value calculation module 10 k, theadjustment value transmission module 10 l, the correction module 10 m,the virtualization module 10 n, and the alternative pattern extractionmodule 10 o may be distributed to a plurality of computers. When thefunctions are distributing to a plurality of computers, communicationmodules, such as a Local Area Network (LAN) and a telephone line, mayconnect each of the computers so that information can be mutually outputand input.

The program storage unit 12 storages the program performed in the CPU 10(the details of the program are described later.). As the programstorage unit 12, for example a recording medium, which can recordprograms, such as a semiconductor memory, a magnetic disk, an opticaldisc, a magneto-optical disc and magnetic tape, can be used.Specifically, a flexible disk, a CD-ROM, an MO disk, a cassette tape andan open reel tape, etc. can be used.

The machine management database 13 includes the error informationstorage unit 13 a for storing the error information on a optical systemerror, the lithography condition storage unit 13 b for storinglithography conditions, an OPE characteristic storage unit 13 c forstoring the optical proximity effect characteristic, the device patternstorage unit 13 d for storing the simulation result of device patterns,the optimal exposure condition storage unit 13 e for storing the optimalexposure conditions for the virtual dangerous patterns, the virtualdangerous pattern storage unit 13 f for storing the virtual dangerouspatterns, the coordinates value storage unit 13 g for storing thedangerous pattern coordinates value, the measurement coordinates valuestorage unit 13 h for storing the measurement coordinates value, anadjustment value storage unit 13 l for storing the adjustment value ofthe projection lens, and the OPC amount storage unit 13 j for storingoptical proximity correction amount, a virtual device pattern storageunit 13 k for storing the virtual device pattern, the machine qualitycontrol information storage unit 13 l for storing the machine qualitycontrol information. Moreover, The optical proximity correction amountstored in the OPC amount storage unit 13 j can be provided by devicesimulation for mask designing etc.

The mask design information database 14 includes a CAD data storage unit14 a for storing the CAD data used in case a mask is designed. Thetemporary storage unit 17 includes a random-access memory (RAM), etc.The RAM stores the information used during program execution of thealigner evaluation program in CPU 10, and functions as an informationmemory used as a work domain. As the input device 15, for example, akeyboard, a mouse, a voice device, etc. can be used. The output device16 is applicable to a liquid crystal display (LCD), a CRT display, aprinter, and the like.

As shown in FIG. 4, each of the aligners 6 a, 6 b, 6 c, . . . , and 6 nof the first factory 5 a include communication I/Fs 61 a, 61 b, 61 c, .. . , and 61 n connected to the communication network 3,transmission/reception modules 62 a, 62 b, 62 c, . . . , and 62 n fortransmitting and receiving information to and from the evaluation server2, the error correction mechanisms 63 a, 63 b, 63 c, . . . , and 63 nfor receiving signals from the evaluation server 2, and exposure units64 a, 64 b, 64 c, . . . , and 64 n for performing exposure by use ofmasks. Reduction projection aligners such as steppers or scanners, andthe like can be provided as the aligners 6 a to 6 n. The measuringdevice 7 a in the first factory 5 a includes a communication I/F 71 aconnected to the communication network 3, a transmission/receptionmodule 72 a connected to the communication I/F 71 a, a measurement unit73 a connected to the transmission/reception module 72 a. Thetransmission/reception module 72 a receives measurement instructioninformation from the evaluation server 2 and transmits a measurementresult thereto through the communication I/F 71 a. The measurement unit73 a measures shapes of patterns and the like. A SEM or a lasermicroscope, for example, may be applied as the measuring device 7 a.

(Aligner Evaluation Method)

Next, description will be made regarding an aligner evaluation methodaccording to the embodiment of the present invention with reference toflowcharts of FIG. 5 to FIG. 7. For the purpose of simplification,description will be made below regarding the plurality of aligners 6 ato 6 n and the measuring device 7 a in the first factory 5 a shown inFIG. 2, as an example. However, it is needless to say that similarprocessing may also actually take place in a global system including alarger group of aligners and a larger group of measuring devices such asthe aligners and the measuring devices located in the second to n-thfactories 5 b to 5 n.

(A) In Step S110, photoresist film coated on wafer surfaces is subjectedto exposure through masks having test patterns for aberrationmeasurement by use of the plurality of aligners 6 a to 6 n shown in FIG.2 and FIG. 4, which are expected to be used to the product development.The photoresist film is then developed and photoresist evaluationpatterns for aberration measurement are delineated on the wafersurfaces. Thereafter, each of the shapes of the photoresist evaluationpatterns provided by the respective aligners 6 a to 6 n is actuallymeasured by use of the measuring device 7 a such as an SEM. Then, themeasurement results of the shapes of the evaluation patterns by themeasuring device 7 a are transmitted to the error calculation module 10a of the evaluation server 2 shown in FIG. 3 through the communicationnetwork 3.

(B) In Step S120, machine evaluation processing for evaluating whetherthe plurality of aligners 6 a to 6 n have the appropriate performancefor implementing an organization of the product development machinegroup is performed in accordance with procedures (a) to (c) as describedbelow.

(a) In Step S121, the error calculation module 10 a calculates theinformation on the errors attributable to differences in aberration ofthe projection lenses, the information on the errors attributable todifferences in the illumination optical systems, and the like, as theoptical system error information among the plurality of aligners 6 a to6 n, based on the measurement results of the photoresist evaluationpatterns received from the measuring device 7 a. The information on theerrors attributable to differences in aberration of the projectionlenses is calculated by conversion into the Zernike coefficients. Theinformation on the errors attributable to differences in theillumination optical systems is quantitatively calculated as the valuesof uneven illuminance, axial misalignment, variation of coherencefactors σ of the illumination optical systems, and the like. Thecalculated optical system error information is stored in the errorinformation storage unit 13 a.

(b) In Step S122, the simulation module 10 b simulates the devicepatterns to be delineated by the respective aligners 6 a to 6 n, basedon the optical system error information, the lithography conditions, themachine quality control information, the CAD data, and the like, whichare obtained from the error information storage unit 13 a, thelithography condition storage unit 13 b, the machine quality controlinformation storage unit 13 l, and the CAD data storage unit 14 a,respectively. Here, the machine quality control information includes thenumerical apertures NA of the projection lenses of the respectivealigners 6 a to 6 n, the coherence factors σ of the illumination opticalsystems, the ring-band ratios, the focal depths, and the like. Thelithography conditions include the exposure amounts, the mask biases,and the like. The simulation results of the device patterns are storedin the device pattern storage unit 13 d.

(c) In Step S123, the evaluation module 10 c evaluates whether each ofthe aligners 6 a to 6 n has the appropriate performances forimplementing the organization of the product development machine group,based on the simulation results stored in the device pattern storageunit 13 d. To be more specific, the evaluation module 10 c evaluateswhether each device pattern simulated by the simulation module 10 bsatisfies the design specifications. Then, the aligners, the devicepatterns of which are evaluated to satisfy the design specifications,for example, the aligners 6 a to 6 f are evaluated to have theappropriate performances for implementing the organization of theproduct development machine group. Regarding the aligners 6 a to 6 f,which are evaluated to have the appropriate performances forimplementing the organization of the product development machine groupby the evaluation module 10 c in Step S123, the procedure advances toStep S130, where actual dangerous pattern confirmation processing takesplace. On the other hand, regarding the aligners which are evaluated notto have the appropriate performances for implementing the organizationof the product development machine group from among the plurality ofaligners 6 a to 6 n, for example, the aligners 6 g to 6 n, the procedureadvances to Step S150, where projection lens adjustment processing takesplace. Moreover, in Step S123, the exposure condition extraction module10 d extracts the respective optimum exposure conditions for the devicepatterns corresponding to the aligners 6 a to 6 n, based on thesimulation results of the device patterns stored in the device patternstorage unit 13 d, the machine quality control information stored in themachine quality control information storage unit 13 l, and the like. Theoptimum exposure conditions to be extracted include the parameters suchas the exposure amounts and the mask biases. The extracted optimumexposure conditions are stored in the optimum exposure condition storageunit 13 e.

(C) In Step S130, regarding the aligners 6 a to 6 f, which are evaluatedto have the appropriate performances for implementing the organizationof the product development machine group in the machine evaluationprocessing in Step S120, the actual dangerous pattern confirmationprocessing for confirming whether the shapes of the actual dangerouspatterns coincide with the shapes of the virtual dangerous patterns isperformed in accordance with the procedures (a) to (d) described below.

(a) In Step S13 l, the virtual dangerous pattern extraction module 10 eshown in FIG. 3 extracts the virtual dangerous pattern out of theplurality of simulated device patterns based on the simulation resultsstored in the device pattern storage unit 13 d. The extracted virtualdangerous pattern is stored in the virtual dangerous pattern storageunit 13 f. The coordinate value extraction module 10 f then extracts thedangerous pattern coordinate values corresponding to the virtualdangerous pattern stored in the virtual dangerous pattern storage unit13 f, out of the CAD data stored in the CAD data storage unit 14 a. Theextracted dangerous pattern coordinate values are stored in thecoordinate value storage unit 13 g. Here, the dangerous patterncoordinate values are values expressed in a CAD coordinate system.

(b) In Step S132, the coordinate system conversion module 10 g convertsthe coordinate system of the dangerous pattern coordinate values storedin the coordinate value storage unit 13 g into a coordinate systemsuitable for the measuring device 7 a, and thereby determines themeasurement coordinate values. The measurement coordinate values arestored in the measurement coordinate value storage unit 13 h. Next, thecoordinate value transmission module 10 h transmits the measurementcoordinate values stored in the measurement coordinate value storageunit 13 h to the measuring device 7 a through the communication I/F 18and though the communication network 3 shown in FIG. 2.

(c) In Step S133, the exposure object (photoresist) on the wafer isexposed by projecting the virtual dangerous pattern under the optimumconditions for each of the aligners 6 a to 6 n, and then the exposureobject is developed to delinate the actual dangerous pattern of thephotoresist. Here, it is also possible to selectively etch a thin filmon a lower layer using the photoresist as a mask, and to use thethin-film pattern on the lower layer as the actual dangerous pattern.Nevertheless, description will be given below regarding the case ofusing the photoresist pattern as the actual dangerous pattern.Thereafter, the wafer having the actual dangerous patterns formedthereon is set on the measuring device 7 a, whereby the shapes of theactual dangerous patterns are actually measured by use of the measuringdevice 7 a while adopting the measurement coordinate values receivedfrom the coordinate value transmission module 10 h as measurementpositions. The measurement results of the shapes of the actual dangerouspatterns are transmitted to the actual dangerous pattern receptionmodule 10 i by the transmission/reception module 72 a through thecommunication network 3.

(d) In Step S134, the confirmation module 10 j compares the shapes ofthe actual dangerous patterns received by the actual dangerous patternreception module 10 i with the shapes of the dangerous patterns storedin the virtual dangerous pattern storage unit 13 f, and therebydetermines whether the shapes of the actual dangerous patterns coincidewith the shapes of the virtual dangerous patterns for each of thealigners 6 a to 6 f. Among the aligners 6 a to 6 f, the aligners, whichdelineates the shapes of the actual dangerous patterns, confirmed ascoincident with the shapes of the virtual dangerous patterns, forexample, the aligners 6 a to 6 c may be used in the product developmentmachine group in Step S140. On the other hand, the aligners whichdelineates the shapes of the actual dangerous patterns which do notcoincide with the shapes of the virtual dangerous patterns in Step S134due to deviation caused by influences attributable to the optical systemerrors and the like, for example, the aligners 6 d to 6 f are subjectedto the projection lens adjustment processing in Step S150 shown in FIG.6.

(D) In Step S150, the projection lens adjustment processing foradjusting each of the projection lenses of the aligners 6 d to 6 n inaccordance with the following Steps S151 and S152. In Step S151, theadjustment value calculation module 10 k calculates the adjustmentvalues for the projection lenses necessary for improving the devicepatterns to be projected on the photoresist, for the respective aligners6 d to 6 n, based on the optical system error information stored in theerror information storage unit 13 a. In Step S152, the adjustment valuetransmission module 10 l transmits the adjustment values for theprojection lenses to the corresponding respective error correctionmechanisms 63 d to 63 n of the aligners 6 d to 6 n through thecommunication network 3. The error correction mechanisms 63 d to 63 nthen adjust the respective projection lenses of the aligners 6 d to 6 nbased on the received adjustment values for the projection lenses.

(E) In Step S160, machine evaluation processing is performed inaccordance with the following Steps S161 and S162, regarding thealigners 6 d to 6 n after adjustment of the projection lenses. In StepS161, the simulation module 10 b simulates device patterns to bedelineated by the respective aligners 6 d to 6 n with the adjustedprojection lenses, based on the optical system error information storedin the error information storage unit 13 a, the adjustment values forthe projection lenses stored in the projection lens adjustment valuesstorage unit 13 i, and the like. The simulation results are stored inthe device pattern storage unit 13 d, and the previously storedsimulation results are thereby updated. In Step S162, the evaluationmodule 10 c evaluates whether the simulated design pattern of each ofthe aligners 6 d to 6 n after adjustment of the projection lensessatisfies the design specifications, i.e. whether each of the aligners 6d to 6 n has the appropriate performances for implementing theorganization of the product development machine group, based on thesimulation results stored in the device pattern storage unit 13 d. InStep S162, among the aligners 6 d to 6 n, the aligners which areevaluated to have the appropriate performances, for example, thealigners 6 d to 6 i are subjected to actual dangerous patternconfirmation processing in Step S170. On the other hand, the alignerswhich are evaluated not to have the appropriate performance, forexample, the aligners 6 j to 6 n advance to Step S180.

(F) In Step S170, the aligners 6 d to 6 i with the adjusted projectionlenses are subjected again to the actual dangerous pattern confirmationprocessing in accordance with the following Steps S171 to S174. In StepS171, the virtual dangerous pattern extraction module 10 e extracts thevirtual dangerous pattern out of the simulated device patterns, based onthe simulation results stored in the device pattern storage unit 13 d.Meanwhile, the coordinate value extraction module 10 f extracts thedangerous pattern coordinate values. In Step S172, the coordinate systemconversion module 10 g converts the coordination system of the dangerouspattern coordinate values into the coordinate system suitable for themeasuring device 7 a, and thereby determines measurement coordinatevalues. The coordinate value transmission module 10 h transmits themeasurement coordinate values to the measuring device 7 a. In Step S173,the measuring device 7 a actually measures shapes of actual dangerouspatterns delineated by projecting the virtual dangerous patterns on theexposure objects with the respective aligners 6 d to 6 i afteradjustment of the projection lenses, while setting the measurementcoordinate values as the measurement positions. The procedure in StepS173 is different from the procedure in Step 113 in that the aligners 6d to 61 with the adjusted projection lenses are used in Step S173. Themeasurement results of the shapes of the actual dangerous patterns bythe measuring device 7 a are transmitted to the actual dangerous patternreception module 10 i through the communication network 3. Theconfirmation module 10 j compares the shapes of the virtual dangerouspatterns stored in the virtual dangerous pattern storage unit 13 f withthe shapes of the actual dangerous patterns received by the actualdangerous pattern reception unit 10 i, and thereby confirm whether theshapes of the actual dangerous patterns coincide with the shapes of thedangerous patterns. In Step S174, among the aligners 6 d to 6 i, thealigners which delineated the shapes of the actual dangerous patternsconfirmed as coincident with the shapes of the virtual dangerouspatterns, for example, the aligners 6 d to 6 f may be used in theproduct development machine group in Step S140. On the other hand, thealigners which delineated the shapes of the actual dangerous patternswhich do not coincide with the shapes of the virtual dangerous patterns,for example, the aligners 6 g to 6 n advance to Step S180.

(G) In Step S180, optical proximity correction processing takes placefor performing optical proximity correction of the aligners 6 g to 6 n.The correction module 10 m updates the parameters such as the exposureamounts and mask biases out of the exposure conditions stored in theoptimum exposure condition storage unit 13 e, based on the opticalproximity correction amounts stored in the OPC amount storage unit 13 j,so as to improve the shapes of the actual dangerous patterns. In thisway, the optical proximity correction is achieved. Alternatively, it isalso possible to correct the numerical apertures NA of the projectionlenses of the aligners 6 g to 6 n, or the coherence factors σ of theillumination optical systems.

(H) In Step S190, the actual dangerous pattern confirmation processingtakes place again in accordance with the following Steps S191 and S192.First, the photoresist on the wafers is subjected to exposure under theexposure conditions after the optical proximity correction by use of thealigners 6 g to 6 n. The photoresist is then developed and the devicepatterns are thereby delineated. Thereafter, in Step S191, the measuringdevice 7 a actually measures the shapes of the actual dangerous patternsout of the delineated device patterns. The confirmation module 10 jconfirms whether the shapes of the actual dangerous patterns coincidewith the shapes of the virtual dangerous patterns. In Step S192, amongthe aligners 6 g to 6 n, the aligners which delineate the shapes of theactual dangerous patterns confirmed as coincident with the shapes of thevirtual dangerous patterns, for example, the aligners 6 g to 6 i may beused in the product development machine group in Step S140. On the otherhand, the aligners which delineate the shapes of the actual dangerouspatterns which do not coincide with the shapes of the virtual dangerouspatterns, for example, the aligners 6 j to 6 n advance to Step S210.

(I) In Step S210, the masks are subjected to optical proximitycorrection. In other words, “optical proximity corrected masks” areordered and fabricated such that dimensions of mask patterns on themasks are modified to achieve the optical proximity amounts which aresuitable for the respective aligners 6 j to 6 n. The optical proximitycorrected masks may be contracted out and fabricated by an outsidesupplier, or may be fabricated at each of the factories 5 a to 5 n andthe like. Thereafter, the newly fabricated optical proximity correctedmasks are placed on the aligners 6 j to 6 n.

(J) In Step S220, the actual dangerous pattern confirmation processingtakes place again by use of the following Steps S221 and S222. First,the photoresist on the wafers is subjected to exposure with the opticalproximity corrected masks by use of the aligners 6 j to 6 n. Then, thephotoresist is developed and the device patterns are thereby delineated.Thereafter, the measuring device 7 a actually measures the shapes of theactual dangerous patterns out of the delineated device patterns. In StepS221, the confirmation module 10 j confirms whether the shapes of theactual dangerous patterns coincide with the shapes of the virtualdangerous patterns. In Step S222, among the aligners 6 j to 6 n, thealigners which delineate the shapes of the actual dangerous patternsconfirmed as coincident with the shapes of the virtual dangerouspatterns, for example, the aligners 6 j to 6 l may be used in theproduct development machine group when the suitable optical proximitycorrected mask is placed on an aligner, in Step S140. On the other hand,the aligners which delineate the shapes of the actual dangerous patternswhich do not coincide with the shapes of the virtual dangerous patterns,for example, the aligners 6 m to 6 n advance to Step S230.

(K) In Step S230, alternative pattern adoption processing for examiningmodification of the design rules of the masks takes place by use of thefollowing Steps S231 and S232. In Step S231, the virtualization module10 n simulates a plurality of virtual device patterns which aredifferent from the device patterns simulated by the simulation module 10b. In Step S232, the alternative pattern extraction module 10 o extractsa pattern, as an “alternative pattern”, which has a different shape fromthe shape of the virtual dangerous pattern not coincident with theactual dangerous pattern in Step S220 but has the identical functionthereto. For example, when the shape of a virtual dangerous pattern oftwo lines does not coincide with the shape of the actual dangerouspattern in Step S220, a pattern of three lines having the identicalfunction as that of the virtual dangerous pattern of the two lines, orthe like is extracted as the alternative pattern by the alternativepattern extraction module 10 o. The extracted alternative pattern isstored in the virtual device pattern storage unit 13 k. Thereafter, thealternative pattern extracted instead of the simulated dangerous patternis adopted to fabricate an “alternative mask” having a different shapefrom the initial mask but having the identical function by use of apattern generator, or the like, such as an electron beam (EB) aligner.The alternative mask may be fabricated by the factories 5 a to 5 n andthe like, or fabricated by an outside supplier. Thereafter, returning tothe machine evaluation processing in Step S120, a series of processingincluding the machine evaluation processing for the product developmentmachine, the actual dangerous pattern confirmation processing, and so onis repeated on each of the aligners 6 m to 6 n equipped with thesuitable alternative masks. When the procedure advances to Step S140,the aligner equipped with the suitable alternative mask, for example,the aligner m may be used in the product development machine group. Onthe other hand, a series of processing including the alternative patternadoption processing, the machine evaluation processing, and so on isrepeated on the aligner which advances to Step 142 again, for example,the aligner 6 n.

According to the aligner evaluation method of the embodiment of thepresent invention, it is possible to promptly, easily, and collectivelyevaluate a plurality of aligners 6 a to 6 n with slightly differentoptical performances as to whether the aligners have the appropriateperformances for implementing the organization of the productdevelopment machine group, and to use the appropriate aligners to theproduct development (mass production).

Note that the aligner evaluating process may be terminated depending onan arbitrary time period or on the number of repeated times of theseries of processing, and the aligner evaluated as inapplicable to theproduct development machine group at the point of termination, forexample, the aligner 6 n may be excluded from the product developmentmachine group.

(Projection Lens Adjustment Processing Modification—1)

Description will be made below regarding one example of the projectionlens adjustment processing in Step S150. First, description will be maderegarding the case of adjusting the projection lens of the aligner 6 awhile the mask has the pattern for delineating a first pattern 21 shownin FIG. 8. The first pattern 21 includes a set of a left pattern 21L anda right pattern 21R having mutually identical shapes. The two patterns21L and 21R have image widths w1 and w2, and image heights h1 and h2,which are mutually of the same dimensions. The two patterns 21L and 21Rare disposed in positions with an interval r therebetween. In Step S121,the error calculation module 10 a calculates sensitivity of the firstpattern 21 with respect to the Zernike coefficients shown in FIG. 9, asthe optical system error information. The lateral axis of FIG. 9represents the Zernike coefficients, and the longitudinal axis thereofrepresents the sensitivity of the first pattern 21. As shown in FIG. 9,the first pattern 21 is sensitive to the seventh term (Z7), thefourteenth term (Z14), and the twenty-third term (Z23) of the Zernikecoefficients showing the wavefront aberration in the Zernikepolynomials.

The projection lens adjustment calculation module 10 k calculates theadjustment values for the projection lens based on the optical systemerror information, such that the adjustment values reduce the aberrationcorresponding to the seventh term, the fourteenth term, and thetwenty-third term of the Zernike coefficients. The adjustment valuetransmission module 10 l then transmits the adjustment values for theprojection lens to the error correction mechanism 63 a of the aligner 6a shown in FIG. 4. The error correction mechanism 63 a adjusts theprojection lens of the aligner 6 a based on the received adjustmentvalues for the projection lens.

The lateral axis of FIG. 10 represents the Zernike coefficients, and thelongitudinal axis thereof represents aberration of the projection lensbefore the adjustment. The lateral axis of FIG. 11 represents theZernike coefficients, and the longitudinal axis thereof representsaberration of the projection lens after the adjustment. By adjusting theprojection lens, it is possible to reduce the amounts of aberrationcorresponding to the Zernike coefficients as shown in FIG. 10 and FIG.11. The lateral axis of FIG. 12 represents slit image heights, and thelongitudinal axis thereof represents lateral differences within anexposure slit of the first pattern 21 delineated by the aligner beforeand after adjustment of the projection lens. The lateral differencebetween the image heights h1 and h2 within the exposure slit of thefirst pattern 21 was about 20 nm at the maximum value d1 beforeadjustment of the projection lens (plotted with diamonds). By contrast,the lateral difference after adjustment of the projection lens (plottedwith squares) is reduced to about 10 nm at the maximum value d2.

(Projection Lens Adjustment Processing Modification—2)

Next, as another example of the projection lens adjustment processing,description will be made regarding the case of adjusting the projectionlens of the aligner 6 b while the mask has the pattern for delineating asecond pattern. The second pattern includes a set of an isolatedlongitudinal pattern 22 a shown in FIG. 13A and a lateral pattern 22 bshown in FIG. 13B, which has the same shape as the longitudinal pattern22 a and is orthogonal thereto. An image width w3 of the longitudinalpattern 22 a and an image height h4 of the lateral pattern 22 b have thesame dimension. An image height h3 of the longitudinal pattern 22 a andan image width w4 of the lateral pattern 22 b have the same dimension,which is about 0.2 μm. As shown in FIG. 14, the error calculation module10 a calculates wavefront aberration of the projection lens for eachslit image height of the longitudinal pattern 22 a (the slit image widthof the lateral pattern 22 b). The lateral axis of FIG. 14 represents theslit image height of the longitudinal pattern 22 a (the slit image widthof the lateral pattern 22 b), and the longitudinal axis thereofrepresents wavefront aberration of the projection lens before theadjustment thereof. As shown in FIG. 14, it is apparent that the secondpatterns 22 a and 22 b are sensitive to the aberration of the projectionlens corresponding to an interaction factor (Z9×Z12) of the ninth term(Z9) and the twelfth term (Z12) of the Zernike coefficients.

The adjustment value calculation module 10 k calculates optical systemerror values for optimizing the ratio, for example, between the ninthterm (Z9) and the twelfth term (Z12) of the Zernike coefficients as theadjustment values for the projection lens. The adjustment valuetransmission module 10 l then transmits the calculated adjustment valuesfor the projection lens to the error correction mechanism 63 b of thealigner 6 b shown in FIG. 4. The error correction mechanism 63 b adjuststhe projection lens based on the adjustment values for the projectionlens.

The lateral axis of FIG. 15 represents the slit image height of thelongitudinal pattern 22 a (the slit image width of the lateral pattern22 b), and the longitudinal axis thereof represents wavefront aberrationof the projection lens after the adjustment thereof. The aberration ofthe projection lens can be reduced as shown in FIG. 15. By adjusting theprojection lens, the lateral axis of FIG. 16 represents the slit imageheight of the longitudinal pattern 22 a (the slit image width of thelateral pattern 22 b), and the longitudinal axis thereof represents thedimensions of the image width w3 of the longitudinal pattern 22 a andthe image height h4 of the lateral pattern 22 b which are delineated bythe aligner 6 b before the adjustment of the projection lens. Thelateral axis of FIG. 17 represents the slit image height of thelongitudinal pattern 22 a (the slit image width of the lateral pattern22 b), and the longitudinal axis thereof represents the dimensions ofthe image width w3 of the longitudinal pattern 22 a and the image heighth4 of the lateral pattern 22 b which are delineated by the aligner 6 bafter the adjustment of the projection lens. A dimensional differencebetween the image width w3 of the longitudinal pattern 22 a and theimage height h4 of the lateral pattern 22 b was about 20 nm at themaximum value d3 before the adjustment of the projection lens as shownin FIG. 16. However, the dimensional difference can be reduced to about5 nm at the maximum value d4 after the adjustment of the projection lensas shown in FIG. 17. The lateral axis of FIG. 18 represents the slitimage height of the longitudinal pattern 22 a (the slit image width ofthe lateral pattern 22 b), and the longitudinal axis thereof representsthe dimensions of the image width w3 of the longitudinal pattern 22 aand the image height h4 of the lateral pattern 22 b which are delineatedby the aligner 6 b after the adjustment of the projection lens andfurther adjustment of uneven illumination. As shown in FIG. 18, thedimensional difference between the image width w3 of the longitudinalpattern 22 a and the image height h4 of the lateral pattern 22 b can befurther reduced by adjusting the uneven illumination after theadjustment of the projection lens. Note that the adjustment values forthe projection lens depend on the design guidelines of each new product,and are not particularly limited.

(Method for Manufacturing a Semiconductor Device)

Next, description will be made regarding a method for manufacturing asemiconductor device (a large-scale integrated circuit: LSI) by use ofthe aligner evaluation system as well as the aligner evaluation methoddescribed above, and the aligner evaluation program, with reference toFIG. 19.

As shown in FIG. 19, the method for manufacturing a semiconductor deviceaccording to the embodiment of the present invention includes adesigning process in Step S100, a mask manufacturing and alignerevaluating process in Step S200, and a chip manufacturing process inStep S300. The mask manufacturing and aligner evaluating process in StepS200 includes the aligner evaluating process using the alignerevaluation system, the aligner evaluation method, and the alignerevaluation program according to the embodiment of the present invention,in addition to the mask manufacturing process. The chip manufacturingprocess in Step S300 includes a pre-process (wafer process) forfabricating an integral circuit on a silicon wafer in Step S310, and apost-process (assembly process) from dicing to inspection in Step S320.Now, description will be made below regarding the details of therespective processes.

(A) First, process mask simulation is carried out in Step S100. Devicesimulation is performed by use of a result of the process masksimulation and each value of currents and voltages to be input to eachof the electrodes. Circuit simulation of the LSI is performed by use ofelectric properties obtained by the device simulation, and a circuitlayout is thereby determined.

(B) In Step S110, photoresist film coated on wafer surfaces is exposed,by use of masks having test patterns for aberration measurement, with aplurality of aligners expected to be used in a photolithography process,for example, the aligners 6 a to 6 n shown in FIG. 2. The photoresist isthen developed and the photoresist evaluation patterns for aberrationmeasurement are delineated on the wafer surfaces. Thereafter, each shapeof the photoresist evaluation patterns provided by the respectivealigners 6 a to 6 n are actually measured by use of the measuring devicesuch as an SEM. Thereafter, the measurement results of the shapes of theevaluation patterns by the measuring device 7 a are transmitted to theerror calculation module 10 a of the evaluation server 2 through thecommunication network 3.

(C) In Step S200, the mask manufacturing and aligner evaluating processtakes place by use of the following procedures (a) to (d).

(a) First, pattern data of the masks (writing mask data) correspondingto respective layers and internal structures of a semiconductor chip aredetermined by use of a CAD system, based on surface patterns such as thecircuit layout determined in the designing process of Step S100.Furthermore, the mask patterns corresponding to the respective processesare delineated on mask substrates made of fused silica or the like, byuse of the pattern data of the masks, with a pattern generator such asan electron beam (EB) aligner, and the masks are thereby fabricated.

(b) Next, the error calculation module 10 a shown in FIG. 3 calculatesthe error information on the mutual optical system errors among theplurality of aligners 6 a to 6 n by use of the measurement resultsobtained in Step S110. The simulation module 10 b then simulates thedevice patterns to be delineated by the respective aligners, based onthe calculated optical system error information (see Step S122 in FIG.5). The evaluation module 10 c evaluates whether the plurality ofaligners 6 a to 6 n have the appropriate performances for implementingthe organization of the product development machine group based on thesimulated device patterns. The aligners evaluated to have theappropriate performance for implementing the organizations of theproduct development machine group, for example, the aligners 6 a to 6 care used in the photolithography processes in Steps S313 a and S313 b.

(c) Meanwhile, the other aligners 6 d to 6 n evaluated not to have theappropriate performances for implementing the organization of theproduct development machine group are subjected to the projection lensadjustment processing (Step S150 in FIG. 6), the optical proximitycorrection processing (Step S180 in FIG. 7), and the like. Thereafter,the determination as to whether the aligners 6 d to 6 n have theappropriate performances for implementing the organization of theproduct development machine group, and other procedures are repeated.The aligners evaluated to have the appropriate performances forimplementing the organization of the product development machine group,for example, the aligners 6 d to 6 f are used in the photolithographyprocesses in Steps S313 a and S313 b.

(d) When a demand arises for fabrication of optical proximity correctedmasks or alternative masks adopting alternative patterns for thealigners 6 g to 6 n which are still evaluated to be unsatisfactory forproduct development in spite of the adjustment of the projection lensesor the optical proximity correction, the suitable optical proximitycorrected masks and the alternative masks are fabricated (see Step S230in FIG. 7). Thereafter, the aligners 6 g to 6 n equipped with theoptical proximity corrected masks or the alternative masks are subjectedto evaluated as to whether the aligners 6 g to 6 n have the appropriateperformances for implementing the organization of the productdevelopment machine group in accordance with the procedures shown in theflowcharts of FIG. 5 to FIG. 7. The aligners evaluated to have theappropriate performance, for example, the aligners 6 g to 61 are used inthe photolithography processes in Steps S313 a and S313 b.

(D) Next, a series of processes including an oxidation process in StepS311 a, a resist coating process in Step S312 a, the photolithographyprocess in Step S313 a, an ion implantation process in Step S314 a, athermal treatment process in Step S315 a, and the like are repeatedlyperformed in a front-end process (substrate process) in Step 310 a. InStep S313 a, photoresist films on semiconductor wafers are exposed bythe step-and-repeat method and thereby patterned, by use of the masksfabricated with the pattern generator in Step S200, with the alignersevaluated appropriate for use in the product development machine groupby the evaluation module 10 c, for example, the aligners 6 a to 6 f. Itis also possible to use the aligners 6 g to 6 i which are equipped withthe alternative masks or the optical proximity corrected masks insteadof the initial masks. When the above-described series of processes arecompleted, the procedure advances to Step S310 b.

(E) Next, a back-end process (surface wiring process) for wiring thesubstrate surface is performed in Step S310 b. A series of processesincluding a chemical vapor deposition (CVD) process in Step S311 b, aresist coating process in Step S312 b, the photolithography process inStep S313 b, an etching process in Step 314 b, a metal depositionprocess in Step 315 b, and the like are repeatedly performed in theback-end process. In Step S313 b, etching masks made of photoresist areformed by exposure using the masks fabricated with the pattern generatorin Step S200 and the aligners 6 a to 6 f evaluated appropriate for usein the product development machine group by the evaluation module 10 c.It is also possible to use the aligners 6 g to 6 i which are equippedwith the alternative masks or the optical proximity corrected masksinstead of the initial masks. When the above-described series ofprocesses are completed, the procedure advances to Step S320.

(F) When a multilayer wiring structure is competed and the pre-processis finished, the substrate is diced into chips with a given size by adicing machine such as a diamond blade in Step S320. The chip is thenmounted on a packaging material made of metal, ceramic or the like.After electrode pads on the chip and leads on a leadframe are connectedto one another with gold wires, a desired package assembly process suchas plastic molding is performed.

(G) In Step S400, the semiconductor device is completed after aninspection of properties concerning performances and functions of thesemiconductor device, and other given inspections on lead shapes,dimensional conditions, a reliability test, and the like. In Step S500,the semiconductor device which has cleared the above-described processesis packaged to be protected against moisture, static electricity and thelike, and is then shipped out.

According to the method for manufacturing a semiconductor device of theembodiment of the present invention, it is possible to promptly selectthe aligners appropriate for use in the product development, out of thealigners 6 a to 6 n in the photolithography processes in Steps S313 aand S313 b. Therefore, it is possible to avoid reduction in yields, toreduce manufacturing costs, and to effectuate mass production in a shorttime.

(Aligner Determining Program)

Next, the details for execution of the instruments of the alignerevaluation program according to the embodiment of the present inventionare described.

The aligner evaluation program according to the embodiment of thepresent invention executes an application on the aligner evaluationsystem, the computer program product provides (A) instructionsconfigured to calculate the error information on the mutual opticalsystem errors among the plurality of aligners 6 a to 6 n; (B)instructions configured to simulate device patterns to be delineatedbased on the error information on the optical system errors, thelithography conditions, the information on the machine quality control,CAD data, etc. respectively stored in the error information storage unit13 a, the lithography condition storage unit 13 b, the machine qualitycontrol information storage units 13 l, and the CAD data storage unit 14a; (C) instructions configured to evaluate whether each of the aligners6 a to 6 n has appropriate performances for implementing theorganization of the product development machine group based on thedevice patterns simulated by simulation module 10 b; (D) instructionsconfigured to extract optimal exposure conditions for the devicepatterns simulated by the simulation module 10 b; (E) instructionsconfigured to extract virtual dangerous patterns from among the devicepatterns simulated by the simulation module 10 b; (F) instructionsconfigured to extract dangerous patterns coordinates value based on theCAD data stored in CAD data storage unit 14 a; (G) instructionsconfigured to convert coordinate system of the dangerous patternextracted by the virtual dangerous pattern extraction module 10 e intothe measurement coordinates values; (H) instructions configured totransmit for the measurement coordinates value calculated by thecoordinate system conversion module 10 g to the measuring device 7 aconnected by the communication I/F 18 through the communication network3; (I) instructions configured to receive the measurement result of theshape of the actual dangerous patterns measured by the measuring device7 a through the communication network 3; (J) instructions configured tocompare the shape of the dangerous patterns received by the actualdangerous pattern reception module 13 l with the shape of the virtualdangerous patterns stored in the virtual dangerous pattern storage unit13 f, and to confirm whether the shape of the actual dangerous patterncorresponds with the shape of the dangerous pattern; (K) instructionsconfigured to respectively calculate the adjustment value of projectionlens of the aligners 6 a to 6 n based on the optical system errorinformation calculated by the error calculation module 10 a; (L)instructions configured to transmit the adjustment value of theprojection lens calculated by the adjustment value calculation module 10k to the optical system errors compensation mechanisms 63 a, 63 b, and63 c, . . . 63 n of corresponding with the each aligner 6 a, 6 b, 6 c, .. . , and 6 n, through the communication network 3 shown in FIG. 2; (M)instructions configured to carry out the optical proximity correctionbased on the shape of dangerous patterns, and the optical proximitycorrection amount; (N) instructions configured to simulate the pluralityof virtual device patterns differing in shape from the device patternssimulated by simulation module 10 b; and, (O) instructions configured toextract the virtual device patterns having the identified function butdiffering in shape from the virtual dangerous pattern as an alternativepattern.

The above-described aligner evaluation program can be stored in acomputer-readable recording medium such as the program storage unit 12.The above-described aligner evaluation system can be achieved byallowing a computer system, such as the CPU 10 shown in FIG. 3, to readthe recording medium so as to execute the aligner evaluation program forcontrolling the computer.

OTHER EMBODIMENTS

The above-described embodiment of the present invention has showed aplurality of (the first to n-th) factories 5 a to 5 n. However, thenumber of factories to be connected to the communication network 3 isnot particularly limited. Moreover, the numbers of aligners and themeasuring devices, which are disposed in each of the first to n-thfactories 5 a to 5 n, and arrangement thereof are not particularlylimited. Furthermore, the evaluation server 2 is located in theheadquarters 1 in the embodiment of the present invention. However, thelocation of the evaluation server 2 is not particularly limited as longas the evaluation server 2 is connected to the communication network 3.For example, the evaluation server 2 may be located inside the firstfactory 5 a or the second factory 5 b.

Various modifications will become possible for those skilled in the artafter receiving the teachings of the present disclosure withoutdeparting from the scope thereof.

1.-20. (canceled)
 21. An evaluation system comprising: an errorcalculation module configured to calculate error information on mutualoptical system errors among plurality of aligners; a simulation moduleconfigured to simulate device patterns to be delineated by each of thealigners based on the error information; an evaluation module configuredto evaluate whether each of the aligners has appropriate performances,which are determined by design specifications required by a product, forelecting a group of appropriate aligners based on the simulated devicepattern; a virtual dangerous pattern extraction module configured toextract a pattern, which is defined by standard values required bydesign guidelines of the product, as a virtual dangerous pattern foreach of the elected aligners among the simulated device patterns; and aconfirmation module configured to compare a shape of the virtualdangerous pattern with a shape of an actual dangerous pattern actuallydelineated by exposing the virtual dangerous pattern on an exposedobject, for each of the elected aligners, so as to determine whethereach of the elected aligners can be used for manufacturing the product.22. The evaluation system of claim 21, further comprising an adjustmentvalue calculation module configured to calculate an adjustment value ofa projection lens for each of the elected aligners based on the errorinformation.
 23. The evaluation system of claim 21, further comprising acorrection module configured to perform an optical proximity correctionbased on the shape of the virtual dangerous pattern.
 24. The evaluationsystem of claim 21, further comprising: a virtualization moduleconfigured to generate a plurality of virtual device patterns differingshape from the simulated device pattern; and an alternative patternextraction module configured to extract alternative pattern differing inshape from the virtual dangerous pattern but having an identicalfunction with the virtual dangerous pattern among the virtual devicepatterns.
 25. The evaluation system of claim 22, wherein the errorinformation pertains to errors attributable to differences of aberrationof projection lenses of the plurality of aligners, and errorsattributable to differences of a illumination optical systems.
 26. Theevaluation system of claim 25, wherein the errors attributable to thedifferences of aberration of the projection lenses is converted intoZernike coefficients.
 27. The evaluation system of claim 25, wherein theerrors attributable to the difference of the illumination opticalsystems is at least one of uneven illuminance, axial misalignment, andvariation of coherence factors of illumination optical systems.
 28. Theevaluation system of claim 21, wherein the evaluation module evaluateswhether each of the simulated device patterns satisfies designspecification.
 29. An evaluation method, comprising: calculating errorinformation on mutual optical system errors from among a plurality ofaligners; simulating device patterns to be delineated by each of thealigners based on the error information; evaluating whether each of thealigners has appropriate performances, which are determined by designspecifications required by a product, for electing a group ofappropriate aligners based on the simulated device pattern; extracting apattern, which is defined by standard values required by design guidelines of the product, as a virtual dangerous pattern for each of theelected aligners among the simulated device patterns; exposing anddelineating the virtual dangerous pattern on an exposed object, andobtaining an actual dangerous pattern for each of the elected aligners;measuring a shape of the actual dangerous pattern; and comparing a shapeof the virtual dangerous pattern with the shape of the actual dangerouspattern for each of the elected aligners, so as to determine whethereach of the elected aligners can be used for manufacturing the product.30. The evaluation method of claim 29, further comprising calculating anadjustment value of a projection lens for each of the elected alignersbased on the error information.
 31. The evaluation method of claim 29,further comprising performing an optical proximity correction for eachof the aligners based on the virtual dangerous pattern.
 32. Theevaluation method of claim 29, further comprising: simulating pluralvirtual device patterns differing in shape from the simulated devicepattern; and extracting alternative patterns differing in shape from thevirtual dangerous patterns but having an identical function with thevirtual dangerous patterns among the virtual device patterns.
 33. Theevaluation method of claim 30, wherein the error information pertains toerrors attributable to differences of aberration of the projectionlenses of the plurality of aligners, and the errors attributable todifferences of illumination optical systems.
 34. The evaluation methodof claim 30, wherein the errors attributable to the differences ofaberration of the projection lens is converted into Zernikecoefficients.
 35. The evaluation method of claim 33, wherein the errorsattributable to the difference of the illumination optical system is atleast one of variation in uneven illuminance, axial misalignment, andcoherence factors of illumination optical systems.
 36. The evaluationmethod of claim 29, wherein the evaluating evaluates whether each of thesimulated device pattern satisfies design specification.
 37. A computerprogram product for executing an application on an aligner evaluationsystem, the computer program product comprising: instructions configuredto calculate error information on mutual optical system errors of aplurality of aligners; instructions configured to simulate devicepatterns to be delineated by each of the aligners based on the errorinformation; instructions configured to evaluate whether each of thealigners has appropriate performances, which are determined by designspecifications required by a product, for electing a group ofappropriate aligners based on the simulated device pattern; instructionsconfigured to extract a pattern, which is defined by standard valuesrequired by guide lines of the product, as a virtual dangerous patternfor each of the elected aligners among the simulated device patterns;and instructions configured to compare a shape of the virtual dangerouspattern with a shape of an actual dangerous pattern actually delineatedby exposing the virtual dangerous pattern on an exposed object, for eachof the elected aligners, so as to determine whether each of the electedaligners can be used for manufacturing the product.
 38. A method formanufacturing a semiconductor device comprising: determining a layout ofa device pattern; preparing a set of masks produced based on thedetermined layout; calculating error information on mutual opticalsystem errors of the plurality of aligners; simulating device patternsto be delineated by each of the aligners based on the error information;evaluating whether each of the aligners has appropriate performances,which are determined by design specifications required by a product, forelecting a group of appropriate aligners based on the simulated devicepattern; extracting a pattern, which is defined by standard valuesrequired by guidelines of the product, as a virtual dangerous patternfor each of the elected aligners among the simulated device patterns;exposing and delineating the virtual dangerous pattern on an exposedobject, and obtaining an actual dangerous pattern for each of theelected aligners; measuring a shape of the actual dangerous pattern;comparing a shape of the virtual dangerous pattern with the shape of theactual dangerous pattern so as to use the elected aligners, whichdelineates the shape of the actual dangerous pattern for each of theelected aligners, so as to determine whether each of the electedaligners can be used for manufacturing the product; coating aphotoresist film on a semiconductor wafer; and exposing the photoresistfilm with one of the masks employing one the aligners, which can be usedfor manufacturing the product.